Trying to drop or modify a function, stored procedure, or DML trigger that is referenced by a plan guide, either enabled or disabled, causes an error.

Disabling a disabled plan guide or enabling an enabled plan guide has no effect and runs without error.

You can execute sp_control_plan_guide with the DROP or DROP ALL option in any edition of Microsoft SQL Server 2005; however, all other options are available only in the Standard and Enterprise editions.

To execute sp_control_plan_guide on a plan guide of type OBJECT (created specifying @type ='OBJECT' ) requires ALTER permission on the object that is referenced by the plan guide. All other plan guides require ALTER DATABASE permission.